Matlab memory issues

I've read the (a?) matlab file on memory on their webiste. Basically, their advice deals with data generation, which I'm not having a problem with. I generated the data sets quite easily on my 64-bit dual core, while simultaneously posting on physicsforums and playing muds.

But once I got the graphical part, my computer kept getting swamped and memory errors kept popping up (no I'm not trying to run muds or browsers with it). Basicallly, I load and plot nine sets of data (axes) on each figure, then save it as a no compression tiff.

I do this all with the visibility off, so I'm supressing graphical output. I make sure to clear the variables before I load new ones.

I can do this once manually with no problems, but if I don't quit matlab and reopen it, the second manual run takes much longer and bogs my computer down (even after matlab has crashed and closed). I got the memory errors initially when I tried to automate the whole data set at once.